1. Field
The present disclosure relates to a template which is used in circular sewing with a sewing machine provided with a circular sewing device in order that a single pattern such as embroidery may repeatedly be formed into a circular arrangement.
2. Related Art
Conventional sewing machines which are capable of selecting one of a plurality of patterns and sewing the selected pattern include a type that can carry out a circular sewing in which a selected pattern is repeatedly sewn into a circular arrangement. Cloth on which the circular sewing is to be carried out is locked at a point by a lock pin. The selected pattern is repeatedly sewn at a number of times while the cloth is being rotated about a lock point. As a result, the selected pattern is repeatedly sewn along a circumference of a circle having a radius r equal to a distance from the lock point A1 to a sewing needle as shown in FIG. 9, for example.
In execution of the above-described circular sewing, it is desirable that a sewing start position of a first sewn pattern should coincide with a sewing end position of a last sewn pattern. However, as shown in FIG. 10, a sewing start position A2 of the first sewn pattern does not sometimes coincide with a sewing end position A3 of the last sewn pattern, whereupon the sewn pattern looks unattractive. In order that a sewing start position of a first sewn pattern may coincide with a sewing end position of a last sewn pattern, a trial sewing is conventionally carried out many times while one or more of parameters including the length, feed pitch and radius of the pattern are changed from one to another. However, this solving manner results in a problem that a large amount of work and a large amount of cloth and thread are wasted.
In view of the foregoing problem, Japanese Patent No. 2573404 discloses a circular sewing method and device in each of which a circumference is obtained from a distance between a lock point of cloth and a needle (a radius in the circular sewing). When the obtained circumference is divided by a length of a pattern and the resultant quotient is not an integer, the length of at least one of the circularly arranged patterns is corrected so that an excess or deficiency is absorbed, whereby a sewing start position of a first sewn pattern coincides with a sewing end position of a last sewn pattern.
In order that the above-mentioned positional coincidence may be achieved in execution of circular sewing in the foregoing Japanese Patent, the sewing machine needs to be provided with computing functions of obtaining the circumference from the distance between the lock point of the cloth and the needle, dividing the circumference by the length of the selected pattern, and correcting the length of at least one pattern when the quotient is not an integer. These computing functions increase costs of the sewing machine.